album to receive a Platinum certification from the Recording Industry Association of America based on distribution alongside a video game. As a result of the underwhelming sales, also credited to the oversaturation of the music game market, the Guitar Hero franchise was put on hiatus until the release of the 2015 reboot, Guitar Hero Live. Gameplay As with previous games in the series, Guitar Hero: Warriors of Rock is a rhythm game, allowing up to four people play in a band on vocals, lead and bass/rhythm guitar, and drums, to use special instrument controllers to simulate the playing of rock music. In general, the goal for each player is to match scrolling note gems that correspond to that instrument's part in the given song to score points; the guitar and bass player must hold down the appropriate colored buttons on the controller and then use the strum bar as the notes pass over a marked zone; the drummer must strike the matching drum pads on the controller when the notes pass, and the vocalist must match the relative pitch of the song's lyrics as guided by phrase markers. Successfully striking notes earns points and boosts the player's performance meter; missing notes will cause this meter to drop. When playing by one's self, if the performance meter should empty, the song will end and require the player to restart it; when playing in a band, the remaining band members must play well enough for a limited time to "revive" a player that has fallen out due to an empty performance meter, or else the whole band will fail the song. Prior to the start of a song, each player can select one of five difficulty levels: Beginner, Easy, Medium, Hard, and Expert, with a sixth difficulty of Expert+ available to some songs on the drums which introduces a double bass pedal. Harder difficulties have characters with high note densities and more difficult playing techniques; each player can select their own difficulty to play. For guitar and bass players, the players are given the opportunity to play single notes or chords, both as single notes or sustained, during which the players must continue to hold down the fret button(s) for the extent of the sustain. Some charts provide the ability to hold down one sustained note via its fret button while strumming additional notes. Warriors of Rock also provides simulated hammer-ons and